[NTLK] MP120, need schematic or anysuggestions

[Eddie Chan]

hi all,
   Thanks to Frank for the advise.  I managed to work on the broken MP120 over the weekend.  I've also taken some photos (see my twitter link below).

   I've tested the fuse labeled "50" and it is fine.  I replaced the 2 x 220uF cap.  I also taken the motherboard our of the case and wired the battery inputs to a power supply (set to 5V & 500mA).

    When I pressed down on the Power slider,  I can hear a chime from the speaker, but no display.  I can see it draw some current ~170mA.  But after awhile, it seems to shut itself down (no current draw).  I checked the voltages on the 2 new capacitors and it shows 6V & 5V.

   This is how far I got so far.  Will continue investigating.

https://twitter.com/maded2/status/1503025852258263047?s=20&t=pJZz2T79ELTPgmzb72cjIw

Eddie

------- Original Message -------

On Wednesday, March 9th, 2022 at 7:19 PM, NewtonTalk <newtontalk at pda-soft.de> wrote:

> > I've just got myself a non-working MessagePad 120, it doesn't boot up.
>
> Make sure you try things with different settings of the contrast wheel. You
>
> wouldn't be the first who deemed his 120 dead because sound was turned off
>
> and contrast was set to minimum.
>
> Since you've mentioned my web site, you've probably already done this, but
>
> in case you haven't, make sure to follow the procedure outlined at the top
>
> of my disassembly page. The key to success is following it to the letter,
>
> not changing anything, regardless of how unimportant the change may seem.
>
> It can't hurt to remove the ROM board, clean its contacts with a pencil
>
> eraser and put it back. Also make sure that the display cable is correctly
>
> seated and its connector is locked. If you have a multimeter, check fuse F1.
>
> It's labeled "50" and lives on the top side of the board (meaning you have
>
> to remove the board to access it) close to the recess for the battery
>
> compartment.
>
> Frank
>
> -- Newton software and hardware at http://www.pda-soft.de
>
> ----------------------------------------------------------------------
>
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>
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